from math import sqrt
import re
# a={1:1,'cc':2,3:3}
# print(",".join(map(str,list(a.keys()))))


# a = "0123456789"
# print(a[::2])


# a = []
# for i in range(2,100):
# 	flag = False
# 	for j in range(2,int(sqrt(i))+1):
# 		if i % j == 0:
# 			flag = True
# 			break
# 	if (flag == False):
# 		a.append(i)

# print(' '.join(map(str,a)))

# a = 3
# b=8
# print(a*b,2*(a+b))

# L = [0, 1, 8, 3.33, 4,7]
# L.sort()
# result = L[(int(len(L)/2))]
# n = str(float(result)).split('.')


# # print(result if n[1] =='0' else '%.1f' % result)

# if len(L) % 2 == 0:
# 	print((sorted(L)[len(L) // 2] + sorted(L)[len(L) // 2 - 1]) / 2)
# else:
# 	print(round(sorted(L)[len(L) // 2],1))

# a = 3
# b = 5
# b为max(a,b)
# if a > b:
# 	a,b = b,a
# print(a,b)

# num = 1
# for i in range(a,0,-1):
# 	if a%i ==0 and b%i ==0:
# 		num = i
# print('最大公约数：',num)


# print('最小公倍数:',int(a*b/num))


# 给你一个正整数列表 L, 输出L内所有数字的乘积末尾0的个数。(提示:不要直接相乘,数字很多,相乘得到的结果可能会很大)。
# L = [4, 2, 25, 7777777, 100, 3, 77777777, 77777777, 77777777, 77777777]
# result = 1
# for i in L:
# 	if(i%2==0 or i%5 ==0):
# 		result = result* i
# num = 0
# for i in str(result)[::-1]:
# 	if i=='0':
# 		num +=1
# 	else:
# 		break

# print(num)

# 方法一、二、三都有可能统计到中间的0
# 方式一：
# num = 0
# for m in str(result):
# 	if m =='0':
# 		num+=1
# 方式二：
# zero = re.findall('[0]',str(result))
# print(len(zero))
# print(num)
# 方式三：
# from collections import Counter
# counter = Counter(str(result))
# print('counter方法：',counter['0'])


# # counter使用
# c = Counter({'red': 4, 'blue': 2}) 
# print(c['blue'])
# print(type(c.elements()))
# c = Counter(cats=5, dogs=8)
# print(c['cats'])
# print(sorted(c.elements()))

# c = Counter('gallahad')
# print(c['a'])
# print(sorted(c.elements()))


# L = ['cats']*4
# print(L)

nums = [2,7,11,15]
target = 9
[(x,y) for i in nums for j in nums]
